NGC 991

{{Short description| Intermediate spiral galaxy in the constellation Cetus }}

{{Infobox galaxy

| name = NGC 991

| image = 250px

| caption = SDSS image of NGC 991

| epoch = J2000

| constellation name = Cetus

| ra = {{RA|02|35|32.68341}}{{cite DR2}}

| dec = {{DEC|-07|09|15.8406}}

| z = 0.005126

| h_radial_v = 1532.8 km/s

| dist_ly = {{cvt|19.28|±|1.37|Mpc|Mly|lk=on|order=flip}}{{cite web|url=https://ned.ipac.caltech.edu/byname?objname=NGC%20991&hconst=67.8&omegam=0.308&omegav=0.692&wmap=4&corr_z=1|title=Results for object NGC 0991 (NGC 991)|work=NASA/IPAC Extragalactic Database|publisher=California Institute of Technology|access-date=2020-06-03}}

| group_cluster =

| type = SAB(rs)c

| size =

| appmag_v =

| appmag_b = 12.36

| absmag_v =

| size_v =

| notes =

| names = {{odlist|UGC=|MCG=-01-07-023|PGC=9846}}{{cite simbad|title=NGC 991|access-date=2020-06-03}}

}}

NGC 991 is an intermediate spiral galaxy the constellation Cetus. This galaxy was discovered by astronomer William Herschel in 1785.{{Cite web|url=http://ned.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=NGC%20991|title=Your NED Search Results|website=ned.ipac.caltech.edu|access-date=2020-03-24}}{{Cite web|url=http://spider.seds.org/ngc/revngcic.cgi?NGC991|title=Revised NGC Data for NGC 991|website=spider.seds.org|access-date=2020-03-24}}{{Cite web|url=https://in-the-sky.org/data/object.php?id=NGC991|title=The galaxy NGC 991 - In-The-Sky.org|last=Ford|first=Dominic|website=in-the-sky.org|language=en|access-date=2020-03-24}}

One supernova has been observed in NGC 991: SN 1984L (type{{nbsp}}Ib, mag. 14) was discovered by Robert Evans on 28 August 1984.{{cite journal | bibcode=1984IAUC.3979....1W| title=Supernova in NGC 991| last1=Waagen| first1=E.| last2=Evans| first2=R.| last3=Cragg| first3=T.| last4=Dunbar| first4=S.| last5=Helin| first5=E.| last6=Barucci| first6=M.| last7=Swanson| first7=S.| journal=International Astronomical Union Circular| date=1984| issue=3979| page=1}}{{cite web | website=Transient Name Server | title=SN{{nbsp}}1984L | url=https://www.wis-tns.org/object/1984L | publisher = IAU | access-date=5 December 2024}}{{cite journal

| title=The peculiar type I supernova in NGC 991

| last1=Wheeler | first1=J. C. | last2=Levreault | first2=R.

| journal=Astrophysical Journal

| volume=294| pages=L17–L20 | date=July 1985

| doi=10.1086/184500 | bibcode=1985ApJ...294L..17W }}